1. Field of the Invention
The subject invention is directed generally to implantable endocardial leads, and more particularly, to an active fixation cardiac lead having a quadripolar connector assembly with a rotatable pin electrode for manually activating the fixation helix at the distal end of the lead.
2. Background of the Related Art
Current implantable active fixation leads are designed with an extendable and retractable fixation helix or screw that can be retracted for transvenous insertion of the lead into the right atrium and ventricle and then extended so that the lead can be actively screwed into the endocardial wall. These are often configured as direct drive leads in which the fixation helix or screw can be extended or retracted by a stylet shaped with a screwdriver tip. An example of an active fixation lead which utilizes a screwdriver tipped stylet is the Physique® cardiac pacing lead manufactured by Oscor Inc. of Palm Harbor, Fla.
It is also known to link the electrode pin of the lead connector assembly of a cardiac lead to the fixation helix of the lead by way of a torque transmitting inner conductor coil. An example of an active fixation lead having an inner torque transmitting coil for activating a fixation helix by way of a rotatable connector pin is disclosed in commonly assigned U.S. Pat. No. 8,150,536 to Osypka, the disclosure of which is incorporated herein by reference in its entirety for purposes of enablement.
Active fixation quadripolar cardiac leads for pacing and/or defibrillation, such as those having IS-4 type in-line connectors, are also known in the art and have been disclosed for example in commonly assigned U.S. Pat. Nos. 7,585,190, 7,422,487 and 8,145,315 to Osypka, the disclosures of which are all herein incorporated by reference in their entireties for purposes of enablement. IS-4 type in-line connectors are configured in accordance with the ISO standard for four-pole (quadripolar) connector systems (PAC/CTF-N151R3) developed by the Connector Task Force (CTF) of the AAMI Pacemaker Committee, which is incorporated by reference herein in its entirety.
It would be beneficial to provide an implantable quadripolar cardiac lead with an IS-4 type connector assembly for manually activating the fixation helix located at the distal end of the lead by way of a torque transmitting conductor coil extending through the lead body.